Select all possible answers: Which statement(s) are true about valence electrons?
a. Atoms are very reactive when they have full valence energy levels.
b. Atoms readily lose or gain valence electrons in order to achieve a full
outer energy level.
c. Atoms are stable when they have as many valence electrons as possible.
d. Valence electrons determine many of the properties of an atom.

The statement(s) which are true about valence electrons are:

c. Atoms are stable when they have as many valence electrons as possible.

d. Valence electrons determine many of the properties of an atom.

An atom refers to the smallest, indivisible unit that isnmade up of matter and forms all chemical elements.

In Chemistry, an atom comprises three (3) distinct particles and these are;

Valence electrons is simply the number of electrons that is/are present in the outermost shell of the atom of a chemical element.

Generally, valence electrons are typically used to determine whether an atom or group of chemical elements can bond with other chemical elements.

As a general rule, atoms with as many valence electrons as possible are more stable and reaches an octet state.

Lastly, valence electrons are used to determine the chemical properties of of the atom of a chemical element.

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c and d are correct

Explanation:

In A, false because in Valence Electrons, the more the valences, the more stable an atom is.

In B, false because atoms cannot readily gain or lose valence electrons as the number of valence electrons is determined by the column they are in.

In C, true because the more the valence electrons, the more the stability of an atom.  

In D, true as electron placing is important and the reactivity of an atom is important.

So C and D are true!

a patient chooses to not take a beneficial medical treatment.

explanation:

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.